Chaltab
Legend
I think you can play it with a lot more freedom, but it's not written in a way that truly facilitates that. It helps that I've seen some really good actual plays of it, including one DMed ENWorlder @BurnsideDescent into Avernus is the nadir of Wizards' horde of freelancers strategy, and from what I've heard, was a very, very troubled production. It's got a great concept, but while the conclusion reads as if the players have a lot of freedom in the middle act, it plays as some linear stories without the deal-making you'd expect where you could go between factions and play them against each other. I can see some groups connect with it, but for me it's just not working.
The behind-the-scenes issues were definitely part of it. Like it originally had nothing to do with Baldur's Gate but then someone looking to maximize brand tie-ins decided that DIA had to tie into Baldur's Gate 3, so the entire Baldur's Gate section (which is like the first 4 levels of the book) was added in after the fact.